Some rail season ticket holders will face fare rises of almost 6% in January, it has been revealed.

An annual ticket from Canterbury in Kent to London will be going up from £4,588 to £4,860 - a 5.9% rise, according to figures from rail customer watchdog Passenger Focus.

Some other Kent travellers - those buying season tickets from Tonbridge to London - will face a 5.2% rise from January 2, with their fare going up to £3,796.

Regulated fares, which include season tickets, will rise by an average of 4.2% from January.

Other fares picked out by Passenger Focus that will rise above this 4.2% average include Northampton to London (up 4.7% to £4,980); Morpeth to Newcastle-upon-Tyne (up 5.0% to £1,008) and Llanelli to Swansea (up 5.4% to £624). Other above-average rises highlighted by Passenger Focus are Bangor-Llandudno (up 5.2% to £1,140) and Ludlow to Hereford (up 5.3% to £1,192).

Some season tickets are not rising as much as 4.2%, while others are on, or very close, to the average. The cost of a season ticket from Shenfield in Essex to London, for example, actually dips in price, from £2,720 to £2,704, while an Ellesmere Port to Chester annual ticket is rising only 2.3% to £720.

Among season ticket fares that are rising by less than 4.0% are Aylesbury-London (up 3.2%), Cambridge-London (up 3.8%), Tain-Inverness (up 3.8%) and Stirling-Glasgow (up 3.9%). The rises could have been steeper but for an intervention by the Government to limit the regulated fare rise to RPI inflation (as of July 2012) plus 1%, rather than the planned RPI plus 3% increase.

Train companies have the flexibility to raise some season tickets above the 4.2% ceiling as long as the average increase on their trains is no more than 4.2%.

Passenger Focus said that it appeared that train companies were exercising restraint but added that the price rises will still feel steep in some places, with the body's chief executive Anthony Smith warning: "Passengers will feel this pain."

Regulated fares account for around 40% of total fares. Train companies can raise non-regulated fares by as much as they like. Details of all fare rises are expected in the next few days.